Adult tickets to a basketball game cost $5. Student tickets cost $1. A total of $3,121 was collected on the sale of 1,249 tickets. How many of each type of ticket were sold?

Let a = # of adult tickets & s = # of student tickets

3121 = 5a + 1s

1249 = a + s

1249 - a = s

3121 = 5a + 1 (1249 - a)

3121 = 4a + 1249

1872 = 4a

a = 468 tickets

so we plug it back into the original equation

1249 = a + s

1249 = 468 + s

781 tickets = s

There were 468 adult tickets and 781 student tickets sold.